Unmanned aerial vehicles (UAVs) are used for a variety of tasks, spanning from recreational activities to commercial operations. Some entities have begun to use UAVs to deliver items to customers. UAVs present many benefits in consumer delivery as they are able to quickly deliver items directly to the customer at a desired customer location while avoiding may challenges faced by traditional delivery types, such as road congestion and human interaction.
In some instances, a UAV operating near the ground (e.g. for package delivery) may lose an ability to resolve its position and orientation (e.g., state estimation). Tracking position and orientation of a UAV with high temporal precision is important for stable autonomous UAV flight. There are many reasons why sensor systems might fail to track position and orientation of the UAV. For example, the UAV may be flying at night or in low light situations where light levels may not enable the camera to capture useful imagery. The vehicle may begin oscillating such that camera motion blur does not allow for useful pictures of the environment for visual navigation and inertial sensors might become saturated. Smoke or other occlusions may be present which may limit use of imagery captured by cameras. The camera or other sensors may simply stop working properly. Communication between systems and/or sensors may be severed.
To successfully execute a flight and delivery, a UAV may be equipped with redundant systems to enable successful outcomes in the event of a malfunction of equipment, such as a malfunction of a sensor or loss of reliable data from a sensor. Having an active backup system which rapidly instruments the environment with purpose built navigation queues may protect a UAV in the event of a failure of a sensor and/or disruption of useful sensor data.